Squash Bugs

While not always a good idea, squashing bugs is the perfect plan when it comes to these garden pests.

If you planted squash in spring, you may be seeing squash bugs in July. Squash bugs (Anasa tristis) use piercing mouthparts to suck plant sap from members of the cucurbit family. This includes melons, pumpkins, summer and winter squash plants. 

Squash bug nymphs (Pollinator) GNU FDL

Squash bug identification and lifecycle

Squash bugs are a little more than 1/2” long. They may be black or gray, and narrow or shield shaped. Squash bugs look like a smaller, flatter version of stink bugs. You may be able to see orange edging around the abdomen and underside of adult squash bugs. Squash bugs lay clusters of 15 - 40 red eggs on the underside of leaves or stems in spring. Two weeks later, whitish spider-like nymphs with black legs emerge. Over the next 4 - 6 weeks, these nymphs will go through several stages (instars) before becoming winged adults.

​Damage caused by squash bugs

Plants infested with squash bugs exhibit speckled leaves that begin to wilt as feeding increases. This wilting may resemble the bacterial wilt spread by cucumber beetles. Squash bugs may also feed on and kill young fruit.

​How to control squash bugs

Sanitation is the best squash bug control method. These pests overwinter under plant debris. You can take advantage of this behavior by leaving small planks out in the garden. In the morning, look underneath the planks and kill any squash bugs found underneath. Also, companion planting research has shown that planting marigold, nasturtium, mint, and radish nearby can repel squash bugs. Trellising your cucurbits can make the environment less hospitable to squash bugs.